Bill McKibben -- who is high on my list of contemporary prophets -- has a powerful article in the current Rolling Stone magazine: "Global Warming's Terrifying New Math." I'm going to give a brief summary and comment. I urge you to read the whole thing.

Bill has managed, once again, to distill technical financial and environmental details into a clear and frightening message. He has packaged this analysis into three core numbers.

2 degrees Celsius (3.6 degrees Fahrenheit). That's the amount of global warming that is broadly considered to be the upper boundary before genuinely catastrophic effects kick in. We're already close to half-way to that level. The current warming of 0.8 degrees C is causing substantial changes in temperatures, extreme weather, ice melting and the closely related effect of ocean acidification. Two degrees is definitely the top end that we can tolerate.

565 gigatons of carbon dioxide. That's how much more CO2 can be released into the atmosphere in the next 40 years and still (potentially) keep under that 2 degree warming. Last year, global CO2 emissions totaled 31.6 gigatons. Some quick math shows that emissions need to decline substantially to keep within the overall budget, but at the current rates of increasing emissions, we're expected to pass the 565 gigaton line in about 16 years. The current trend of fossil fuel use is pointing toward a temperature increase of 6 degrees C (11 degrees F), "which would create a planet straight out of science fiction."

2,795 Gigatons. "The number describes the amount of carbon already contained in the proven coal and oil and gas reserves of the fossil-fuel companies, and the countries (think Venezuela or Kuwait) that act like fossil-fuel companies. In short, it's the fossil fuel we're currently planning to burn. And the key point is that this new number -- 2,795 -- is higher than 565. Five times higher."

To keep global warming below catastrophic levels, 80% of those known fossil fuel deposits need to be kept in the ground. Which means not tapping into tar sands in Alberta and Venezuela, not drilling for oil and gas in the Arctic and deep oceans, not scraping up coal to feed power plants around the world, and not using up all the conventional oil in Saudi Arabia, Iraq and Russia. To keep below 2 degrees of warming, those resources have to be left where they are.

But here's the frightening detail that McKibben adds to the mix. "Yes, this coal and gas and oil is still technically in the soil. But it's already economically aboveground -- it's figured into share prices, companies are borrowing money against it, nations are basing their budgets on the presumed returns from their patrimony."

He continues, "at today's market value, those 2,795 gigatons of carbon emissions are worth about $27 trillion. Which is to say, if you paid attention to the scientists and kept 80 percent of it underground, you'd be writing off $20 trillion in assets." That is a huge, unprecedented hit to the balance sheets of businesses and governments.

Naomi Klein has said that "these numbers make clear that with the fossil-fuel industry, wrecking the planet is their business model. It's what they do." Those industries are using their immense financial and political power to preserve and expand their wealth and their assets. And governments are totally complicit in continuing this trajectory, continuing to sell leases for oil and coal fields, continuing to subsidize the industry that is ruining the planet. The economic and political trends are pointing toward the use of all those reserves, toward burning five times more carbon than the planet can take.

+ + + + +

McKibben's message of hope, and his description for a course of action, is appropriately economic. He points out the reason that those fossil fuel reserves are so obscenely valuable, and says that we can change the unique feature that favors the industry.

"Alone among businesses, the fossil-fuel industry is allowed to dump its main waste, carbon dioxide, for free. ... If you put a price on carbon, through a direct tax or other methods, it would enlist markets in the fight against global warming."

Putting a price on carbon can be done in ways that don't bankrupt citizens -- with a "fee-and-dividend" approach -- but doing so will reduce the profitability of the fossil fuel industries. If the price of carbon goes up, the value of their reserves goes down.

And this is where Bill McKibben reveals himself as a prophet, not a conventional activist. To get a price on carbon, he says, will require moral outrage leading to a broad movement for change. For an example of how this can happen, he points to the successful global movement for liberation in South Africa, where pension funds, colleges, and local governments divested their financial holdings from companies connected to the apartheid regime. Denominational pension funds, by the way, were some of the leading forces for this socially responsible investment strategy in the 1980s.

A leader of the Investor Network on Climate Risk said, "The message is simple: We have had enough. We must sever the ties with those who profit from climate change – now."

+ + + + +

McKibben's article has been gnawing at me this week. He has put together key pieces of our situation with clarity and urgency. His three numbers reveal why we are destined for an unimaginable climate disaster unless a high price is put on the carbon that is still in the ground. Unless a carbon tax dramatically cuts the $27 trillion value of those fossil fuel reserves, all of that coal, oil and gas will be burned -- and our planet will be toast.

I hold to a deep hope that faith communities can and will be leaders in a new moral movement for that change in carbon pricing. We have what it takes: lots of people in the pews and on our mailing lists, a deeply-grounded ethical perspective that is global and long-term, and significant assets in pension funds and investment portfolios.

In some churches -- but nowhere near enough -- we've started to get involved with campaigns to change light bulbs or install solar panels. Some of us have taken on specific issues like mountaintop removal and pipelines for Canadian tar sands. We're waking up to the crisis and doing some good things, and we need to do much more.

McKibben's three numbers tell us that we have to use everything we have -- especially our moral outrage and our financial clout -- to change the economic rules by imposing a high price on carbon's pollution. We have to be bold, passionate and faithful in public witness as we stand for the health and vitality of the whole Earth community.